def paint(self, painter, option, widget = None):
QGraphicsPolygonItem.paint(self, painter, option, widget)
pen = QPen(QColor("yellow"))
pen.setWidth(10)
painter.setPen(pen)
painter.drawPoint(self.entrance())
pen.setColor(QColor("magenta"))
painter.setPen(pen)
painter.drawPoint(self.exit())
for c in self.connectors[2:]:
painter.drawPoint(c)
pen.setColor(QColor(0,255,255))
pen.setWidth(2)
painter.setPen(pen)
painter.drawEllipse(self.cog(), 5, 5)
